Computing device display screen or portion thereof with a graphical user interface



The attached FIGURE illustrates a computing device display screen or portion thereof with a graphical user interface showing the new design. The broken lines shown in the FIGURE represent portions of the computing device display screen and graphical user interface that form no part of the claimed design.

The attached FIGURE is a front view of a computing device display screen or portion thereof with a graphical user interface in accordance with the claimed design. 

CLAIM The ornamental design for a computing device display screen or portion thereof with a graphical user interface, as shown and described. 